title: Perioperative risk factors for prolonged mechanical ventilation after liver transplantation due to acute liver failure.
abstract: BACKGROUND
  Acute liver failure (ALF) is a rapidly progressing and fatal disease for which liver transplantation (LT) is the only treatment. Posttransplant mechanical ventilation tends to be more prolonged in patients with ALF than in other LT patients. The present study examined the clinical effects of prolonged posttransplant mechanical ventilation (PMV), and identified risk factors for PMV following LT for ALF.
  
  
  METHODS
  We reviewed data of patients undergoing LT for ALF between January 2005 and June 2011. After grouping patients according to administration of PMV (≥ 24 h), donor and recipient perioperative variables were compared between the groups with and without PMV. Potentially significant factors (P < 0.1) from the univariate intergroup comparison were entered into a multivariate logistic regression to establish a predictive model for PMV.
  
  
  RESULTS
  Twenty-four (25.3%) of 95 patients with ALF who received PMV had a higher mortality rate (29.2% vs 11.3%, P = 0.038) and longer intensive care unit stay (12.9 ± 10.4 vs 7.1 ± 2.7 days, P = 0.012) than patients without PMV. The intergroup comparisons revealed worse preoperative hepatic conditions, more supportive therapy, and more intraoperative fluctuations in vital signs and less urine output in the with- compared with the without-PMV group. The multivariate analysis revealed that preoperative hepatic encephalopathy (≥ grade III), intraoperative blood pressure fluctuation, and oliguria (< 0.5 ml/kg/h) were independent risk factors for PMV.
  
  
  CONCLUSIONS
  PMV was associated with deleterious outcomes. Besides care for known risk factors including hepatic encephalopathy, meticulous attention to managing intraoperative hemodynamic circulatory status is required to avoid PMV and improve the posttransplant prognosis in ALF patients.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Serin
authors.initials: S
authors.lastname: Lee
authors.forename: Hyun Sik
authors.initials: HS
authors.lastname: Jung
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Choi
authors.forename: Jaemin
authors.initials: J
authors.lastname: Lee
authors.forename: Sang Hyun
authors.initials: SH
authors.lastname: Hong
authors.forename: Sung Hyun
authors.initials: SH
authors.lastname: Lee
authors.forename: Chul-Soo
authors.initials: CS
authors.lastname: Park
keywords: Acute liver failure; Liver transplantation; Mechanical ventilation; Prediction